Base unit for assembling a crankcase of a reciprocal compressor

ABSTRACT

A base unit for assembling a crankcase of a reciprocal compressor comprises a housing configured to hold at least part of a crankshaft; an access port placed onto the housing and configured to hold a connecting rod for a piston; the base unit having at least an interface zone on the housing, configured to be coupled with another interface zone of another base unit for assembling the crankcase.

BACKGROUND

The present embodiments relate to a base unit for assembling a crankcase of a reciprocal compressor.

A crankcase for a reciprocating compressor is known in the art. Such a crankcase is designed to hold the crankshaft, which is placed along a predefined orientation. The orientation of the crankshaft defines a longitudinal axis of the crankcase. Such a crankcase includes a housing, which has the function of holding the crankshaft. The housing has two sidewalls, which develop substantially parallel to each other and to the longitudinal axis of the crankcase.

A plurality of access ports are located on the side walls. Each access port allows a respective connecting rod, which is in turn connected to a piston, to attach to the crankshaft. The access ports are arranged on the side walls in such a way as to balance the load on the crankshaft itself during the normal functioning of the compressor.

A disadvantage of the known crankcase is that it is manufactured by casting and it is tailor-made for the specific application. This also applies to very big crankcases, which can house, for example, a crankshaft with up to ten pistons. Therefore, a faulty cast has the consequence of wasting an entire crankcase, with corresponding productivity and economic losses.

BRIEF DESCRIPTION

A first aspect is therefore a base unit for assembling a crankcase of a reciprocal compressor. Such a base unit includes a housing configured to hold at least part of a crankshaft. An access port is placed onto the housing, and is configured to hold a connecting rod attached to a piston. The base unit has at least an interface zone, also placed on the housing, which is configured to be coupled with another interface zone of another base unit in order to assemble the crankcase.

The base unit may allow a modular approach to the assembling of a crankcase, since many base units can be assembled in order to build a crankcase according to the specifications. In turn, this allows an increased productivity of the fabrication process.

A second aspect is a kit for assembling a crankcase including a plurality of base units. At least a connecting device is provided in order to attach the base units to each other onto the respective interface zones. This allows for optimization of the assembly procedure for the reciprocating compressors.

A third aspect is a crankcase including at least a base unit as described above.

A fourth aspect is therefore directed to a method for assembling the crankcase. The method includes the steps of providing at least two base units and attaching the base units to each other onto the respective interface zones.

A fifth aspect is therefore directed to a method for upgrading a crankcase. This method includes the step of providing a further base unit. This further base unit can be attached to the crankcase, in particular by placing an interface zone of the new base unit into contact with the interface zone of a base unit already part of the crankcase. This has the feature of being able to update an already built crankcase instead of having to build a new one.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details and specific embodiments will refer to the attached drawings, in which:

FIGS. 1 and 2 are perspective views of a first embodiment of a base unit for assembling a crankcase of a reciprocal compressor; and

FIG. 3 is a perspective view of a detail of a second embodiment of a base unit for assembling a crankcase of a reciprocal compressor.

DETAILED DESCRIPTION

The following description of exemplary embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the embodiments. Instead, the scope of the application is defined by the appended claims.

Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

Therefore, a base unit for assembling a crankcase 101 of a reciprocal compressor will be described, also referring the attached figures in which it will be indicated with the number 1.

The base unit 1 includes a housing 2, which is configured to hold at least part of a crankshaft 100. Indeed, the housing 2 has a longitudinal axis “A”, which defines an orientation for the crankshaft 100. The housing 2 has a first end 2 a and a second end 2 b, opposite to each other and substantially aligned along the longitudinal axis “A”. The longitudinal axis “A” lays on a longitudinal plane which is transversal with respect to both the first end 2 a and the second end 2 b.

The housing 2 is substantially U-shaped and has an open side from which the crankshaft 100 can be inserted. Once the crankshaft 2 has been placed in the housing 2, a plurality of crosspieces 17 are installed on the housing 2 in order to increase the structural rigidity of the housing 2 itself.

With additional detail, the housing 2 includes a support plate 11. In an embodiment, the support plate 11 is rectangular in shape, and is configured to rest onto a support surface (not shown).

In an embodiment, the housing 2 has two end walls 8, which are placed on the ends 2 a, 2 b of the housing 2. The end walls 8 are substantially perpendicular to the above mentioned longitudinal plane. In another embodiment, the end walls 8 are substantially parallel to each other. In use, the end walls 8 are oriented substantially in a vertical direction, and thus are transversal, and, in an embodiment, perpendicular, to the support plate 11.

With more detail, each end wall 8 has a seat 9 configured to accept a crankshaft 100 of suitable size. In particular, the seat 9 has a concave, semicircular shape so that it is able to receive bearings (not shown). A closure 12 can be placed onto the seat 9 in order to lock the shaft 100 in the seat 9.

In an embodiment, the housing 2 also includes two side walls 10, placed transversally and perpendicularly to the above mentioned end walls 8. The side walls 10 are substantially parallel to each other. Such side walls 10 are each attached to a further housing 13, which is designed to hold a crosshead for a piston (not shown in the drawings). According to different embodiments, the further housings 13 can either be made as a single piece with the housing 2 or they can be built separately and then attached to the housing 2 in a later phase.

With more detail, an access port 3 is placed onto the housing 2. Such an access port 3 is configured to hold a connecting rod for a piston (not shown in the drawings). Specifically, the access port 3 is placed onto the side wall 10, so that the above mentioned connecting rod can link the crosshead to the shaft 100 inside the base unit 1. In the embodiments shown in the figures each side wall 10 has a single access port 3. In different embodiments, not shown, each side wall can have more than one access port 3.

According to the embodiments shown in the attached figures, the base unit 1 has at least an interface zone 4 on the housing 2. In an embodiment, the interface zone 4 lays on a plane transversal to the longitudinal axis “A” of the housing 2. In detail, the interface zone 4 is configured to be coupled with another interface zone 4 of the base unit 1 for assembling the crankcase 101. In other words, two base units 1 can be joined together in order to assemble a crankcase 101. Details on the method for assembling a crankcase 101 will be given in a following portion of the present disclosure.

The base unit 1 has two interface zones 4, which are placed respectively onto the first end 2 a and onto the second end 2 b of the housing 2. Indeed, the interface zones 4 are parallel to each other. In an embodiment, this allows to chain-link an arbitrary number of base units 1. With additional detail, each interface zone 4 is placed onto a respective end wall 8. In particular, each interface zone 4 is placed onto an outer surface 8 a of the end walls 8. The base units are arranged so that their open sides face on the same side.

With additional detail, the interface zone 4 is provided with at least a socket 5, which is configured to receive a connecting device (not shown). The connecting device has the function of fixing the interface zone 4 to another base unit 1. In an embodiment, the interface zone 4 is provided with at least two sockets 5, placed on opposite sides of the longitudinal plane of the housing 2. Indeed, in the embodiments shown in the figures the interface zone 4 is provided with a plurality of sockets 5, placed substantially symmetrically with respect to the longitudinal plane.

With greater detail, the embodiment from FIGS. 1 and 2 is provided with twelve sockets 5. Specifically, the sockets 5 are arranged so that there are six sockets 5 on each side of the longitudinal plane.

Similarly, the embodiment from FIG. 3 is provided with four sockets 5. These sockets 5 are arranged so that there are two sockets 5 on each side of the longitudinal plane.

In further embodiments, not shown in the drawings, there can be any number of sockets 5. In an embodiment, the number of the sockets 5 and their arrangement are the same on each interface zone 4 of the base unit 1. Alternatively, if justified by design considerations, the number of the sockets 5 and their arrangement can differ between the two interface zones 4.

According to the embodiments shown in the attached figures, each socket 5 is a hole 6. In an embodiment, either a centering pin or a bolt (both are not shown in the figures) can be installed in the holes 6.

An embodiment also relates to a kit for assembling a crankcase 101. Such a kit includes one or more base units 1, such as the one described above. A suitable number of connecting devices is provided, so that the base units 1 can be attached together. In particular, the base units 1 can be attached on their respective interface zones 4, as explained above.

Optionally a spacer device 15 can be inserted between two base units 1. Such a spacer device is used in case the cylinders that have to be attached to the crankcase 101 are particularly large. Indeed, if that is the case, a suitable spacer device 15 used so that enough space is restored between two base units 1. Specifically, the spacer device 15 has two ends 15 a, which are opposite and which can be attached to a respective base unit 1 as will be explained in a following part of the present disclosure.

With greater detail, the spacer device 15 includes at least a perimetral wall 14. In use, such a perimetral wall 14 extends around the crankshaft 100. In the embodiment shown in the figures, the spacer device 15 includes just one perimetral wall 14 which is U-shaped. This particular shape of the spacer device 15 allows the admittance of the crankshaft from the open side of spacer device 15. Both the spacer device 15 and the base unit 1 have the open sides face on the same side in order to allow the entry of the crankshaft 100. In alternative embodiments, not shown, the spacer device 15 can include any number of perimetral walls 14 which can be arranged differently.

In detail, the spacer device 15 is configured to be connected to the base units 1 onto the respective interface zones 4. Indeed, the spacer device 15 has a pair of interface zones 16 itself. These interface zones 16 are opposite to each other. In other words, the interface zones 16 are each placed onto a respective end 15 a of the spacer device 15. The interface zones 16 are configured to be attached to respective interface zones 4 of respective base units 1. For this reason, the interface zones 16 are substantially similar to the interface zones 4 of the base unit 1, therefore they will not be further detailed in the present disclosure.

Although a known crankshaft can be used with the crankcase 101 according to the above described embodiment, the kit can also include a crankshaft 100 configured to be inserted into the housing 2 of the base unit 1. In detail, the crankshaft 100 includes a plurality of segments 102. Each segment 102 is configured to be housed into a respective base unit 1 and to be joined with at least another segment 102 in order to define the crankshaft 101. In other words, the crankshaft 100 is also modular, being composed by a variable number of segments 102. In an embodiment, each segment 102 has a length substantially equal to the length of its respective base unit 1 along the longitudinal axis “A”. Furthermore, in an embodiment, the number of segments 102 is the same as the number of base units 1 in the crankcase. In an embodiment, each segment 102 is configured to be attached to two connecting rods.

Additionally, the crankshaft may include one or more further segment 103. Each further segment 103 is configured to be attached to two segments 102. In an embodiment, each further segment 103 has the same length along the longitudinal axis “A” as the spacer device 15. Indeed, in use, each further segment 103 is placed inside the spacer device 15.

In an embodiment, in each kit the base units 1 have all the same length along the longitudinal axis “A”. This may enable a better modularity for the crankcase 101 built using the above described kit. Of course such length can vary depending on design specification. Furthermore, if necessary a single kit can include base units 1 of different length or size.

Another embodiment relates to a method for assembling the above described crankcase 101. Two or more of the base units 1 are provided with the appropriate number of spacer device 15.

These base units 1 are attached to each other. Optionally, if the spacer devices 15 are used, they are each inserted between two base units 1. The interface zones 4, 16 are joined. In particular, pins (not shown) are inserted inside a subset of sockets 5. The remaining sockets 5 of adjacent interface zones 4, 16 are then secured with bolts. A crankshaft is inserted in the seats 9 of the base units 1. If necessary, a crankshaft 100 is assembled by any required number of segments 102 and further segments 103, which are joined by means known to the person skilled in the art.

Another embodiment relates to a method of upgrading a crankcase 101, for example if an additional pair of pistons (with respective connecting rods) is deemed necessary. In this case, another base unit 1 is attached to a base unit 1 already part of the crankcase 101, in particular at one end of the crankcase 101. If necessary, a spacer device 15 can be inserted between the previous crankcase 101 and the new base unit 1. Also, if a known single-piece crankshaft was installed in the previous crankcase 101 it has to be replaced. Otherwise, if the above discussed crankshaft 100 was used, it can be adjusted by adding a new segment 102 and, if required, a new further segment 103. Any number of base units 1 can be added this way.

It is to be understood that even though numerous characteristics and advantages of various embodiments have been set forth in the foregoing description, together with details of the structure and functions of various embodiments, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. It will be appreciated by those skilled in the art that the teachings disclosed herein can be applied to other systems without departing from the scope and spirit of the application. 

What is claimed is:
 1. A base unit for assembling a crankcase of a reciprocal compressor, comprising: a housing configured to hold at least part of a crankshaft; and an access port placed onto the housing and configured to hold a connecting rod for a piston; wherein the base unit has at least one interface zone on the housing, and the at least one interface zone being configured to be coupled with another interface zone of another base unit for assembling the crankcase.
 2. The base unit according to claim 1, wherein the housing has a longitudinal axis defining an orientation for the crankshaft, and the at least one interface zone laying on a plane transversal to the longitudinal axis.
 3. The base unit according to claim 2, wherein the housing has a first end and a second end opposite to each other and substantially aligned along the longitudinal axis, wherein the at least one interface zone comprises two interface zones placed respectively onto the first end and onto the second end of the housing.
 4. The base unit according to claim 3, wherein the two interface zones are parallel to each other.
 5. A base unit according to claim 1, wherein the at least one interface zone is provided with at least a socket configured to receive a connecting device for fixing the at least one interface zone to another base unit.
 6. The base unit according to claim 5, wherein the socket comprises a hole adapted to receive either a screw or a pin.
 7. A base unit according to claim 1, wherein the housing has an open side configured to admit the crankshaft.
 8. A kit for assembling a crankcase comprising: a plurality of base units according to claim 1; and at least a connecting device configured to attach two of the base units to each other onto the respective interface zones.
 9. The kit according to claim 8, further comprising a spacer device insertable between two base units and configured to be connected to the base units onto the respective interface zones.
 10. The kit according to claim 9, wherein the spacer device has two interface zones opposite to each other and configured to be attached to respective interface zones of respective base units.
 11. The kit according to claim 8, further comprising a crankshaft configured to be inserted into the housing.
 12. The kit according to claim 11, wherein the crankshaft comprises a plurality of segments for assembling the crankshaft, and each crankshaft segment being configured to be housed into a respective base unit and to be joined with at least another crankshaft segment in order to define the crankshaft.
 13. The kit according to the claim 12, wherein each segment has a length substantially equal to the length of its respective base unit along the longitudinal axis.
 14. The kit according to claim 8, wherein the base units have all the same length along the respective longitudinal axis.
 15. A crankcase comprising at least a base unit according to claim
 1. 16. The crankcase according to claim 15, the crankcase being assembled from a kit comprising: a plurality of base units according to claim 15; and at least a connecting device configured to attach two of the base units to each other onto the respective interface zones.
 17. A method for assembling a crankcase according to claim 15, comprising the steps of: providing at least two of the base units; and attaching the base units to each other onto the respective interface zones.
 18. The method according to claim 17, further comprising the step of inserting a spacer device between the base units.
 19. The method for upgrading a crankcase according to claim 15, comprising the steps of: providing a further base unit, and attaching the further base unit to the crankcase.
 20. The method according to claim 19, wherein the step of attaching the further base unit to the crankcase is performed by placing an interface zone of the further base unit into contact with an interface zone of a base unit already part of the crankcase. 